Within the topic about API to send a temporary password to a user (restore password) it has been described that Backendless free plan allows a temporary password generated by the backend system to be sent by API.
However, with a paid plan, the same API works differently. Rather than sending a computer-generated password, user receives in an email a link to a customizable page where they can choose their own password.
The webpage which Backendless uses by default is loaded from the file storage allocated to a developer's Backendless backend. It can be seen at the /web/templates/change_password/ directory:
The text of the email can also be modified. See the instructions from the topic on how to change the text of the email for password recovery.